<template>
  <image
    :mode="node.attr.mode"
    :lazy-load="node.attr.lazyLoad"
    :class="node.classStr"
    :style="newStyleStr || node.styleStr"
    :data-src="node.attr.src"
    :src="node.attr.src"
    @tap="wxParseImgTap"
    @load="wxParseImgLoad"
  />
</template>

<script>
export default {
  name: 'WxParseImg',
  props: {
    node: {
      type: Object,
      default() {
        return {}
      }
    }
  },
  data() {
    return {
      newStyleStr: '',
      preview: true
    }
  },
  methods: {
    wxParseImgTap(e) {
      if (!this.preview) return
      const { src } = e.currentTarget.dataset
      if (!src) return
      let parent = this.$parent
      while (!parent.preview || typeof parent.preview !== 'function') { // TODO 遍历获取父节点执行方法
        parent = parent.$parent
      }
      parent.preview(src, e)
    },
    // 图片视觉宽高计算函数区
    wxParseImgLoad(e) {
      const { src } = e.currentTarget.dataset
      if (!src) return
      const { width, height } = e.mp.detail
      const recal = this.wxAutoImageCal(width, height)
      const { imageheight, imageWidth } = recal
      const { padding, mode } = this.node.attr
      const { styleStr } = this.node
      const imageHeightStyle = mode === 'widthFix' ? '' : `height: ${imageheight}px;`
      this.newStyleStr = `${styleStr}; ${imageHeightStyle}; width: ${imageWidth}px; padding: 0 ${+padding}px;`
    },
    // 计算视觉优先的图片宽高
    wxAutoImageCal(originalWidth, originalHeight) {
      // 获取图片的原始长宽
      const { padding } = this.node.attr
      const windowWidth = this.node.$screen.width - (2 * padding)
      const results = {}

      if (originalWidth < 60 || originalHeight < 60) {
        const { src } = this.node.attr
        let parent = this.$parent
        while (!parent.preview || typeof parent.preview !== 'function') {
          parent = parent.$parent
        }
        parent.removeImageUrl(src)
        this.preview = false
      }

      // 判断按照那种方式进行缩放
      if (originalWidth > windowWidth) {
        // 在图片width大于手机屏幕width时候
        results.imageWidth = windowWidth
        results.imageheight = windowWidth * (originalHeight / originalWidth)
      } else {
        // 否则展示原来的数据
        results.imageWidth = originalWidth
        results.imageheight = originalHeight
      }

      return results
    }
  }
}
</script>
